Retailers are partnering with a company that knows how to make mediocrity respectable.
The big box retailers understand they have a service gap to fill as our aging population becomes ever less inclined to tackle do-it-yourself projects. That's why most of the players have started "installed sales" programs. For a single quoted price, customers can buy their water heaters, faucets, disposals, etc., and have someone install the products. The work is usually subbed out to a local network of independent contractors.
Retailers are not exactly jumping for joy over this setup. Most credible contractors don't find the installation fees high enough to make it worthwhile for them to participate. It's the kind of deal that tends to attract the garage-shop operators, who often are not very reliable or customer friendly. Home Depot and the other big boxes take a PR beating every time they dispatch Billy Joe Buttcrack to do their work, and it costs them money when they have to make good on failed commitments.